Southern California -- this just in

Officials don't know when Bay Bridge will reopen; welding finished but safety test is next [Updated]

October 28, 2009 | 12:36
pm

Crews completed welding on a section of the San Francisco-Oakland Bay Bridge that failed Tuesday but the repair still needs to be tested for safety, a spokeswoman for the California Department of Transportation said today.

Officials said they still did not know when the bridge will be reopened to traffic.
The bridge was closed after two rods and a 5,000-pound crossbeam fell during rush hour traffic at 5:30 p.m. Tuesday.

Three cars were damaged and a driver suffered minor injuries.
The portion that collapsed was part of a repair done over the Labor Day weekend.

That repair was made after crews discovered a cracked link during a seismic safety upgrade.

The rods that snapped held a cap over the cracked link.

The closure left commuters scrambling for alternative routes,
whether that meant taking other bridges or using mass transit.

BART
subway lines were jammed this morning, and the agency said it was
bringing in more trains.

Motorists were asked to use the Golden Gate Bridge, the Richmond/San Rafael Bridge and the San Mateo Bridge.

Officials said they were grateful no one was badly hurt in the incident, which might have been related to heavy winds.

"If you look at the totality of the circumstances -- you've got the
5:30 commute, you have a 5,000-pound piece of steel falling out of the
sky. We are so fortunate that no one was injured or killed," California
Highway Patrol Sgt. Trent Cross told KTVU-TV.

[Updated at 2:20 p.m.: The rods that snapped held a “clamp” that was supposed to keep the fractured link together, said UC Berkeley civil engineering professor Abolhassan Astaneh-Asl. He said the repair was not designed to withstand high winds or earthquakes.

“This was not designed correctly,” he said. “The combination of the weight of the traffic and the force of the wind exceeded the capacity of this temporary repair.”

In an earthquake, the kind of bar that cracked would “completely fracture,” he said. “As soon as that one member fractures, the entire bridge collapses.”

He said the bridge should be shut down for a few days so that all the relevant bars can be inspected for hairline cracks with X-ray equipment. The repair should not be the same design that failed Tuesday, he said.]